Method of anchoring hair-like synthetic filaments to a wig base

ABSTRACT

A METHOD IS HEREIN DESCRIBED FOR LOCKING HAIR-LIKE SYNTHETIC FILAMENTS FORMED FROM SUCH MATERIALS AS ACRYLIC AND MODACRYLIC TO A WIG STRUCTURE BY CHEMICALLY UNITING THE FILAMENTS AT THEIR ATTACHED POSITION WHEREBY THE FILAMENTS ARE FIRMLY SECURED IN THAT THEY REMAIN ATTACHED AND DO NOT LOOSEN UPON BRUSHING AND COMBING THE WIG STRUCTURE.

. 3,687,752 METHOD OF aucaonme HAIR-LIKE SYNTHETIC FILAMEN'I'S TO A W16BASE Filed Sept. 4, 1970 Aug. 29, 1912 F. s. RIORDAN, JR

FILAMENTS ASSEMBLED IN PARALLEL ALIGNMENT SECURE FILAMENTS ALONG ASTITCH LINE ATTACH STITCHED FILAMENTS' TO CONTOURED BASE COALESCEFILAMENTS ALONG STITCH LINE DRY United States Patent 3,687,752 PatentedAug. 29, 1972 3,687,752 METHOD OF AN CHORING HAIR-LIKE SYNTHETICFILAMENTS TO A WIG BASE Frank S. Riordan, Jr., St. Louis, Mo., assignorto Monsanto Company, St. Louis, Mo. Filed Sept. 4, 1970, Ser. No. 69,892Int. Cl. A41g 5/00; B32b 5/02 US. Cl. 156-72 2 Claims ABSTRACT OF THEDISCLOSURE A method is herein described for locking hair-like syntheticfilaments formed from such materials as acrylic and modacrylic to a wigstructure by chemically uniting the filaments at their attached positionwhereby the filaments are firmly secured in that they remain attachedand do not loosen upon brushing and combing the wig structure.

BACKGROUND OF THE INVENTION (1) Field of the invention (2) Descriptionof the prior art Contoured bases or foundations in the head covering artare known by various names as hairpieces, wigs and toupees. In this art,the expert must effect a simulated hair growth pattern of filamentarymaterial by arranging such material on the exterior surface of varioustypes of 'foundation pieces, such as bases, skull caps and the like,which are often of net or weblike material.

In the head cover art relating to wigs and hairpieces there are severalconventional types of covers designated as stretch, hand-tied and semihand-tied Wigs. In general, the stretch wigs are characterized by havingtheir hair-like filaments sewn into a weft which consists of fibergroupings with thread lock stitches holding the groupings in place. Ahand-tied wig is constructed by tying as through knotting a plurality offilaments to a netted wig substrate. The semi hand-tied wig ischaracterized by lateral wefting at and around the crown and none at themarginal edge of the foundation piece of the head cover.

In the production of wigs, it is common practice to employ hairlikefilaments formed from synthetic polymers. As is often the case, suchpolymers have as an integral part of the polymer chain or intimatecontact therewith a number of chemical modifying agents added toovercome for the most part certain inherently undesirable propertiesassociated with a particular synthetic polymer. Thus, it is known in theart that polymers of polyacrylonitrile do not have good flame resistantproperties. In order to overcome this difiiculty, a number of flameretarding substances are employed. Further, often there are numerousdifliculties associated with obtaining a suitable dye receptiveness soas to produce the shades of color desired by the trade. As topolyacrylonitrile resort is often made to the use of various dyereceptive monomers incorporated in the polymer chain. In addition, avariety of coatings may be selected in order to lubricate an advancingfilament during a conventional stitching or needling operation. Sufficeit to say that when filaments are finally implanted within a substrateafter such treatments, there are often difficulties associated withfirmly connecting it to substrate by conventional means. That is to say,as is often the case, the advantage rendered by chemical treatment carrysome inherent disadvantages with respect to certain compositestructures. One particular problem to which this invetnion is addressedis the objectionable behavior, especially after chemical treatment, forfilaments which are more or less physically tied to a fabric substanceto become easily loosened and detached from said substrate by gentleforces.

Attempts heretofore have been made to solve the above mentioned problem,but they have not proven satisfactory. For example, it has been proposedto apply a latex-like layer and to allow the same to dry so as to anchorthe hair-like synthetic filaments to a woven fabric, or to use a solidthermoplastic material and thereafter subjecting the thermoplasticmaterial to the action of heat to plasticize the same so that it anchorsthe filaments to the fabric, or to employ netting devices to firmlysecure the filaments in place. These former methods are more or lessobjectionable for several reasons in that they all involve theapplication of a substantial layer to a composite fabric and involveadding a layer which is often times quite bulky and sticky.

The method of embodying the invention herein is an improvement in theabove category of known methods with novel features being provided inthe anchoring method to be more fully described hereafter.

SUMMARY OF THE INVENTION In production of wigs, it is conventional tosecure a plurality of filaments to form a wetting and to secure this toa netted wig substrate. It is often the case that in the regularmaintenance of a wig, a number of filaments become loosened and arepulled out from their base to give an unsightly appearance.

It is therefore an object of this invention to provide a novel methodfor anchoring synthetic hair filaments so that they remain attached tothe wig substrate and do not become dislodged therefrom.

The attainment of this object is accomplished by partially dissolving bya suitable solvent a plurality of filaments in intimate association soas to coalesce and to unite them.

The accompanying drawing depicts the process of the invention. Thesequence of assembling, securing, attaching, coalesing and dryingacrylic fibers is shown therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with my method aplurality of synthetic hair-like filaments are first assembled in a sideby side arrangement and stitched to secure them to form a wefting, thestitching transversing the wefting and locking the filaments intogroupings and leaving the distal ends of the filaments projectingoutwardly, securing said wefting to a contoured base to form a wigstructure and thereafter partially dissolving the filaments at theirattached portion whereby that portion of the filaments coalesce and flowinto one another and finally drying the dissolved portions of saidfilaments to firmly bond them together.

In one embodiment of my invention, a plurality of acrylic filaments areplaced in a side by side arrangement, the length of said filaments beingsubstantially uniform, stitching the plurality of filaments transverselyto secure them together, the filaments being so secured so as to allowthe ends thereof to extend outwardly, partially dissolving that portionof the filament in contact with and in proximity to a stitch line so asto coalesce that portion of the filaments to one another, drying thedissolved portion to form a stable wefting and attaching the wefting toa contoured base to simulate a natural growth pattern. The preparedwefting is generally attached to the base by sewing it to form a wigstructure. At any rate, it can be readily 3 appreciated that the partialdissolusion and drying of the filaments may be done before attaching theprepared wefting to the contoured base.

It is contemplated that after stitching a wefting along its length tosecure the filaments, the wefting may be attached to a contoured baseand thereafter anchored in position by partially dissolving that portionof the filaments in contact with the stitch line. For this embodi ment,an acrylic solvent is sprayed in the form of a fine mist onto theunderside portion of the cap of a headpiece to apply the solvent nearand along the stitch line. The solvent may preferably be applied in theform of an aerosol.

It will be evident from this invention that the binding method is farsuperior to the binding in use in numerous respects. The method of thisinvention serves to reinforce the stitched section of the strip so thatthe filaments do not pull out in the course of time. The filamentsremain firmly in position over the areas of the strip and cannot bereadily dislodged. Moreover, the new binding method does not add to thethickness of the wig base and generally gives an attractive appearance.Moreover, the use of my method effects a saving in manufacture in thatno supplemental devices or fabric layers are required.

The plurality of filaments are arranged in substantially parallelalignment, the filaments being of a more or less uniform length. Thefilaments may be folded along their length to form a loop. The foldedportions are secured in place by a line of stitching which passesthrough the body of the fabric. The stitching thread may be of variousmaterials, but preferably should be of some staple material as nylon.The thread material may be inert to and non-soluble in the solventemployed to partially dissolve the hair-like filaments to be used, Asoluble thread may also be employed to effect a *firm bond to theimplanted hair-like filaments with no added disadvantage.

The solvents of this invention include ethylene carbonate, propylenecarbonate and trimethylene carbonate in a diluent such as a loweraliphatic glycol as propylene and ethylene glycol. Of course, aqueoussolutions of said carbonates may also be advantageously employed. Also,other solvents may be used, such as dimethyl sulfone, tetramethylenesulfone, and dimethyl formamide. These may be dissolved in water, or maybe dissolved in alcohol, ethylene glycol, benzene or the like. Water andethylene glycol are preferred diluents. The range of solventconcentration may be from as little as 0.5 percent to 50 percent byweight. Common solvents for modacrylics are the ketones such as acetone.The diluents serve as a liquid vehicle inert to the material acted uponby the aforedescribed solvents.

In partially dissolving portions of the filaments, it is important thatthe solvent be only applied to that portion of the filaments in contactwith and in proximity to the stitch line.

The dissolution of the filaments may be accomplished by drawing thewefting along said stitch line through a trough containing a solventwith an appropriate diluent. Sponging, brushing, or padding the solventdirectly onto the filaments may also be done when the wefting isattached to the hairpiece foundation or prior to being attached to thefoundation. Spraying via nozzles or nozzle-like means may also beemployed to evenly distribute the solvent. Spraying may also be usedafter the wefting is attached to the foundation. The spray pattern inthis latter case should conform more or less to that of the contouredbase to be treated. The spray pattern in issuing upward and fallingdownward assumes approximately a hemispherical projection. Thus, inorder to spray effectively a hairpiece upon the underside portionthereof said underside portion is exposed so that it substantiallyoverlaps with that of the projected spray pattern. For proper coveragefor the head of a wearer, the filaments should freely separate one fromthe other except for the anchored portion along the stitch line. Thus,

4 when spraying from a nozzle the issuing solvent must play upon theunderside of the wig and be applied to the aforementioned portion.

Although spraying the solvents herein described has been mentioned asthe preferred method of applying the solvent, conventional paddingprocedures may also be employed.

A filler may be admixed with the solvent. A wide array of fillers may beemployed in conjunction with the solvent. Fillers such as silica, silicaaerogel or finely divided precipitated silicas may be employed as wellas TiO alumina, diatomaceous earth, crushed quartz, ferric oxide andcalcium carbonate. It is best that there be from 5 to 15 percent byweight of these fillers. Amounts above or below the above specifiedrange either decrease the bonding of the filaments or provide nobeneficial effect.

Partial dissolution of the hair-like filaments is accomplished byexposing portions of the filaments in contact along the stitch line fora time and at a temperature suflicient to solvate the external sectionsof said filaments so that upon drying the filaments so treated no longerassume their original shape. In effect, the hair-like filaments at theirpoint of contact spread toward one another and unite to formsubstantially a unitary structure. Generally, the temperature of thesolvent-diluent may range from about 50 C. to the boiling point atatmospheric pressure for at least one second until dissolution.

Drying may be accomplished by heating the treated structure in aconventional fabric drying apparatus to evaporate and to concentratesolvent and diluent. Upon drying, a durable bond between and among thefilaments is formed. If an aqueous ethylene carbonate solution is usedalone, the exact temperature of drying is immaterial as long as thefilaments so treated are dried; however, the temperature of drying mustnot go into the degradation point of the acrylic or modacrylic fibers,viz., 350 F. Of course, the drying may be done at room temperature or atan elevated temperature, depending upon the solvent employed. Aconventional fabric drying apparatus, such as a chain dryer may be used,to evaporate the solvent-diluent. It is necessary that the dryingresults in concentrating the solvent so as to bond the filaments attheir lower portions in contact with the stitch line to form a durablebond between and among themselves.

The term modacrylic denotes a fiber-forming substance of any long chainsynthetic polymer composed of less than 85% but at least 35% by weightsof acrylonitrile units, (CH CHCN),,. Polyacrylonitrile copolymers,including binary and ternary polymers of at least percent by weight ofacrylonitrile units denote the acrylic materials herein. While thepreferred polymers employed in the instant invention are thosecontaining at least 80 percent of acrylonitrile, generally recognized asthe fiberforming acrylonitrile polymers, it will be understood that theinvention is likewise applicable to polymers containing less than 80percent acrylonitrile.

The polymer may be a copolymer of from 80 to 98 percent acrylonitrileand from 2 to 20 percent of another monomer containing the c=c linkageand copolymerizable with acrylonitrile. Suitable mono-olefinic monomersinclude acrylic, alpha-chloroacrylic and methacrylic acids; theacrylates, such as methylmethacrylate, ethylmethacrylate,butylmethacrylate, methoxymethyl methacrylate, beta-chloroethylmethacrylate and the corresponding esters of acrylic and alpha-chloroacrylic acids; vinyl chloride, vinyl fluoride, vinyl bromide, vinylidenechloride, 1 chloro-bromo ethylene; methacrylonitrile, acrylamide andmethacrylamide; alpha-chloroacrylamide; or monoalkyl substitutionproducts thereof; methylvinyl ketone carboxylates, such as vinylacetate, vinyl chloroacetate, vinyl propionate, and vinyl stearate;N-vinylimides, such as N-vinylsuccinimide methylene malonic esters;itaconic acid and itaconic esters; N-vinylcarbazole; vinylfurane; alkylvinyl esters; vinyl sulfonic acid, ethylene alpha, beta-dicarboxylicacids or their anhydrides or derivatives, such as diethylcitraconate,diethylmesaconate, styrene, vinyl naphthalene; vinyl-substitutedtertiary heterocyclic amines, such as the vinylpyridenes andalkylsubstituted vinylpyridines, for example, 2-vinylpyridine,4-vinylpyridine, 2-methyl-5-vinylpyridine, etc., l-vinylimidazole andalkyl-substituted l-vinylimidazoles, such as 2-, 4-, or5-methyl-l-vinylimidazole, and other c-c containing polymerizablematerials.

The polymer may be a ternary or higher interpolymer, for example,products obtained by the interpolymerization of acrylonitrile and two ormore of any of the monomers, other than acrylonitrile, enumerated above.More specifically, and preferably the ternary polymer comprisesacrylonitrile, methacrylonitrile, and 2-vinylpyridine. The ternarypolymers preferably containing from 80 to 98 percent of acrylonitrile,from 1 to percent of a vinylpyn'dine or a l-vinylimidazole, and from 1to 18 percent of another substance such as methacrylonitrile or vinylchloride.

The polymer may also be a blend of a polyacrylonitrile or of a binaryinterpolymer of from 80 to 99 percent acrylonitrile and from 1 to 20percent of at least one other c=c containing substance with from 2 to 50percent of the weight of the blend of a copolyrner of from 10 to 70percent of acrylonitrile and from to 90 percent of at least one otherc=c containing polymerizable monomer. Preferably, when the polymericmaterial comprises a blend, it will be a blend of a copolymer of 90 to98 percent acrylonitrile and from 2 to 10 percent of anothermono-olefinic monomer, such as vinyl acetate, which is not receptive todyestulf, with a sufiicient amount of a copolymer of from 10 to 70percent of acrylonitrile and from 30 to 90 percent of a vinylsubstitutedtertiary heterocyclic amine, such as vinylpyridine or l-vinylimidazole,to give a dyeable blend having an overall vinyl-substituted tertiaryheterocyclic amine content of from 2 to 10 percent, based on the weightof the blend. It will be apparent that different embodiments of thisinvention may be made without departing therefrom.

Having thus described my invention, what I desire to claim and secure byLetters Patent is:

1. A method of anchoring synthetic hair-like filaments to a wigstructure, comprising the steps of:

assembling a plurality of filaments in a side by side arrangement, theindividual filaments being of substantially uniform length and insubstantially parallel alignment, said filaments being polymers of thegroup consisting of acrylic and modacrylic;

stitching the plurality of filaments transversely of their length tosecure the filaments together into groupings of filaments leaving thedistal ends of said filaments extend outwardly of a stitch line;

attaching the stitched plurality of filaments to the exterior section ofa contoured base to simulate a natural growth pattern;

partially dissolving by exposing the underside partions of the contouredbase and thus the filaments in contact with and in proximity to thestitch line whereby those portions of said filaments coalesce and flowinto one another, the partial dissolution being effected by a solventcomprising from about 0.5 to about weight percent of compounds selectedfrom the group consisting of ethylene carbonate, propylene carbonate,trimethylene carbonate, dimethyl sulfone, tetramethylene sulfone,dimethyl formamide, acetone, and mixtures thereof, and from about 50 toabout 95.5 weight percent of a liquid vehicle; and

drying the dissolved portions of said filaments to firmly bond themtogether.

2. The method of claim 1 wherein the solvent contains colloidal silica.

References Cited UNITED STATES PATENTS 3,307,562 3/1967 Corbett et a1.l3255 3,357,878 12/1 967 Newman 15 6-296 3,530,862 9/1970 Hudson 13253BE'NJAMIN A. BORCHELT, Primary Examiner I. V. DORAMUS, AssistantExaminer US. Cl. X.R. 1325 6

